1. Field of the Invention
The present invention relates to a toner cartridge for use in an electrophotographic image recording apparatus.
2. Description of the Related Art
A conventional print process cartridge for an electrophotographic printer uses a toner cartridge that is designed to detachably mounted. Toner is discharged from the toner cartridge into a toner reservoir. The toner is agitated by an agitator and supplied to a developing unit.
Then, a developing roller applies the toner to a photoconductive drum which has an electrostatic latent image formed thereon, thereby developing the electrostatic latent image with the toner into a toner image. The toner image is then transferred by a transfer roller to a print medium. The toner image on the print medium is then fixed and the print paper is finally discharged from the printer.
A small amount of toner fails to be transferred from the photoconductive drum to the print paper and remains on the photoconductive drum. A variety of cleaning methods are available to collect the residual toner on the photoconductive drum during the cleaning process. A desirable cleaning method is such that a cleaning unit requires a smaller space for storing the waste toner. One such method is to return the residual toner as waste toner to the toner cartridge, so that the toner cartridge can be discarded with the waste toner collected therein.
This type of toner cartridge has a chamber for waste toner adjacent to a chamber for fresh toner, these two chambers being aligned in the longitudinal direction of the toner cartridge. Thus, the total length of the toner cartridge is the sum of the lengths of the fresh toner chamber and the waste toner chamber.
An opening formed in the toner cartridge is fitted to a waste toner exit of the print process cartridge, thereby coupling the toner cartridge to the print process cartridge. The waste toner is finally collected into the waste toner chamber of the toner cartridge through the waste toner exit.
The toner cartridge has a shutter mechanism formed near the opening. When the toner cartridge is disconnected from the waste toner exit of the print process cartridge, the shutter closes the opening to prevent the waste toner from falling through the opening from the toner cartridge.
As described above, the toner cartridge is relatively long due to the fact that the fresh toner chamber and the waste toner chamber are aligned in the longitudinal direction of the toner cartridge. The printer needs to be wide to accommodate a longitudinally long toner cartridge. If the waste toner chamber is made shorter in an attempt to reduce the width of the printer, the fresh toner chamber also has to be made shorter. If the fresh toner chamber has a length shorter than the width of a print region, the fresh toner may not be evenly supplied across the width of the print region, resulting in poor print quality.
Providing a shutter that closes the opening to prevent inadvertent spillage of toner from the toner cartridge requires a large number of mechanical parts which results in a complex mechanism. Such a complex mechanism causes frequent troubles and misuses.
The present invention was made in view of the aforementioned drawbacks.
An object of the invention is to provide a toner cartridge having a shorter longitudinal dimension than conventional toner cartridges, thereby implementing a miniaturized toner cartridge.
A toner cartridge extending in a longitudinal direction thereof, comprising a fresh toner chamber and a waster toner chamber. The fresh toner chamber extends in the longitudinal direction of the toner cartridge. The waste toner chamber extends parallel to the fresh toner chamber so that the fresh toner chamber and the waste toner chamber are aligned in a direction perpendicular to the longitudinal direction.
The fresh toner chamber has an opening through which the toner is discharged from said fresh toner chamber, a shutter, an operating lever, and a locking mechanism. The shutter closes the opening when the operating lever is at a first position at which the operating lever is locked by the locking mechanism and opens the opening when the operating lever is at a second position opposite to the first position.
The waste toner chamber has an entrance formed at one of opposed longitudinal ends of the waste toner chamber. The waste toner chamber receives waste toner through the entrance from outside. There is provided a toner-conveying member such as a screw conveyor in the waste toner chamber. The screw-conveying member extends between the opposed longitudinal ends, becoming higher with increasing distance from the first one of the opposed longitudinal ends and causing the waste toner to move further into the waste toner chamber. The toner-conveying member may extend in a horizontal direction and have a spiral blade on a part of the length thereof.
The waste toner chamber has a resilient member fitted into the entrance. The resilient member having a slit formed therein through which the waste toner exit enters the waste toner chamber when the toner cartridge is attached to the print process cartridge.
The resilient member is folded at said slit when the resilient member is fitted into the entrance.
The waste toner chamber has a flexible sleeve-like sealing member fitted to the entrance. The sealing member has one end opening to communicate with the opening of the waste toner chamber and another end normally resiliently closed. The closed end resiliently opens when the waste toner exit enters into the waste toner chamber through the sleeve-like sealing member, and resiliently closes when the waste toner exit comes out of the waste toner chamber.
The resilient member may be urged by a spring against the entrance. When the waste toner exit enters the waste toner chamber through the entrance, waste toner exit pushes the resilient member to yieldably move away from the entrance, thereby opening the entrance. When the waste toner exit moves out of the waste toner chamber through the entrance, the sprint urges the resilient member against the entrance, thereby closing the entrance.
The toner cartridge and the print process cartridge may have polarizers that matingly match each other, so that only a right toner cartridge can be attached into a corresponding location of the print process cartridge. This feature prevents misplacement of the toner cartridge in the print process cartridge.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.